Tumour necrosis factor receptor-associated periodic syndrome (TRAPS),1 formerly known as familial Hibernian fever,2 3 is an archetypal hereditary periodic fever syndrome and is an autosomal dominant condition characterised by mutations in the TNFRSF1A gene.4 5 Periodicity of fevers is typical of TRAPS, with peritonitis, arthritis and fasciitis. It is also well recognised that some patients continue to feel unwell between attacks. That subclinical TRAPS is still ongoing in such circumstances is supported by persistent acute phase response.6 7 There are no specific features to localise a site for this persistent inflammatory response and, to date, no studies have been done to investigate this interesting observation.

Whole body MRI has recently been introduced for the assessment of various skeletal pathologies including malignancy, myositis and arthritis.8,–,12 MRI …